1. integral from 0 to pi of (4 sin theta -3 cos theta) d theta

I started like this...4 integral from 0 to pi of sin theta d theta -3 integral from 0 to pi cos theta d theta...I got stuck here

what do you mean you "got stuck"? do you know the antiderivatives of sine and cosine ? do you know how to use the fundamental theorem of calculus?

2. How do I calculate this math?

3/4 (8^4/3) - 3/4 (1^4/3) =?

1 to any power is 1.

3. How do I solve this integral?

integral of cos^3 x dx

straight up integration of the first integral ... use substitution for the second , let